By utilizing rectorite as matrix, the mesoporous solid superacid in form of pillared clays (SO₄^2-/SiZrR), pillared by Si-Zr bipillaring agent and modified subsequently by SO₄^2-, was prepared. Its structure was characterized by means of XRD, BET, FT IR, Hammett indicator, NH₃-TPD, Py-IR, DTA etc. The results show that after being calcined at 500℃, SO₄^2-/SiZrR exhibited superacidity and mesoporous structure with the Hammett acidity function H_o-11.93 and the most probable pore size at ca. 2.3 nm. The superacid sites were attributed to Lewis acid sites and proved to be dominant active center. The Si-Zr bipillars can enhance the thermal stability of the resulting catalysts substantially. By utilizing rectorite as matrix, the thermal stability of pillared clay is, in particular, higher than that of pillared clay which utilizes montmorillonite as matrix.

Key words: rectorite, mesoporous solid superacid, catalyst, structure characterization